Acidic aqueous iodine concentrates



United States Patent 3,308,014 ACIDIC AQUEOUS IODINE CONCENTRATES Abraham Cantor, Elkins Park, Pa., and Otto E. Neracher, Mount Vernon, and Murray W. Winicov, Flushing, N.Y., assignors to West Laboratories, Inc., Long Island City, N .Y., a corporation of New York No Drawing. Filed Mar. 30, 1962, Ser. No. 183,740 2 Claims. (Cl. 167-17) This invention relates to acidic aqueous iodine concentrates particularly useful as starting components in the formulation of detergent-iodine compositions. More particularly, the invention relates to acidic aqueous iodine concentrates wherein iodine in the presence of concentrated aqueous hydroxyacetic acid, is solubilized in the hydroxyacetic acid by means of a water soluble iodide (I-) in an amount equal to at least 50% by weight based on the weight of iodine.

In the formulating of various detergent-iodine preparations, particularly when moderately to highly acid products are desired for various environmental sanitation purposes, the prob-lems of properly combining the components to form stable commercial products become troublesome for the small formulator. Special mixing equipment is required, and without proper controls, it is possible to encounter problems, such as excessive viscosity, precipitation of iodine, excessive loss of iodine by reaction with the detergent, and the like. There is therefore, a distinct need for an acidic aqueous iodine concentrate which can be combined directly with detergent, or detergent and water using simple mixing equipment to formulate consumer products without the danger of encountering the problems above mentioned.

It is now discovered in accordance with the present invention that an aqueous acidic iodine concentrate having these advantages can be prepared, utilizing hydroxyacetic acid as the acidifying agent, and supplying iodine in the form of an aqueous iodine-iodide solution in which the iodide (1"), present in an amount equal to at least 50% by Weight, based on the weight of iodine, acts to solubilize the iodine in the hydroxyacetic acid in all practical proportions. While amounts of iodide slightly less than 50% by weight of the iodine can sometimes be employed, the important factor is that this amount is suflicient to solubilize the iodine in the hydroxyacetic acid. Amounts of iodide in substantial excess of 50%, based on the weight of the iodine provide no special advantage with respect to iodine solubility in the concentrate. In other words, the proportion of iodide of about 50% by weight, based on the weight of iodine, and suflicient to solubilize the iodine in the hydroxyacetic acid should be considered as a minimal preferred proportion.

The solubilizing eifect of iodide on iodine in an acidic aqueous concentrate appears to be a special eifect peculiar to concentrates in which the acidifying agent is hydroxyacetic acid. Phosphoric acid 'has been widely used as an acidifying agent for detergent-iodine formulations. Phosphoric acid, however, is quite unsuited for use in an acidic aqueous iodine concentrate of the type herein described. It has been found, for example, that in a 50% phosphoric acid solution containing as high as 15% iodide (1") only 5% iodine can be solubilized. In contrast to this, 50% of hydroxyacetic acid can solubilize over 15% of iodine with as little as 7.5% iodide present. At higher acid concentrations, the difference in behavior is even more striking.

The iodide in the new aqueous acidic iodine concentrates can be in the form of any water soluble iodide, such as alkali metal iodides, hydriodic acid, and the like, with hydriodic acid being preferred.

The following example will serve to show how typical acidic aqueous iodine concentrates in accordance with the present invention can be prepared, but it is to be under- Example A number of concentrates were prepared by adding to quantities of commercial concentrated (70%) hydroxyacetic acid, aqueous iodide-iodine solutions containing 50% by weight iodine and either 25% by weight of hydriodic acid or 29.5% sodium iodide (in which the proportion of iodide (I-) is approximately 50% based on the weight of iodine), and other aqueous iodide-iodine solutions in which the proportion of iodide (I) to iodine is varied above and below 50%.

In the following tabulation, Table A shows the compositions of a number of typical satisfactory concentrates, Whereas Table B shows the compositions of closely related, but unsatisfactory concentrates:

TABLE A.-SATISFACTORY CONOENTRATES Percent Hydroxy- Percent Available Percent Iodide (I-) acetic Acid Iodine TABLE B.UNSATISFACTORY CONCENTRATES Percent Hydroxy- Percent Available Percent Iodide (I) acetic Acid Iodine In each of the concentrates listed in Table B, a portion of the iodine precipitates on combining with hydroxyacetic acid. Upon filtering off several of these precipitates, the stable filtered concentrates were found in each instance to contain a reduced amount of available iodine equivalent to approximately twice the amount of hydriodic acid noted in the table.

While the satisfactory concentrates shown in Table A include concentrations of hydroxyacetic acid ranging from about 5 to 65% and concentrations of iodine ranging from 5 to 45%, it is considered that concentrates most suitable for use in preparing detergent-iodine formulations are those which contain about 20 to 50% hydroxyacetic acid and 10 to 25% iodine, with the iodide (1) in each instance being equal to at least 50% by weight based on the weight of iodine.

It will, of course, be understood that the selection of particular concentrates for use in formulations of acidic detergent iodine preparations will depend upon the particular type of consumer product being prepared. The formulator of a consumer product would first determine the type and amount of detergent desired in relation to the germicidal activity and degree of acidity desired in the product. A concentrate can then be supplied having the proper balance of hydroxyacetic acid to iodine, so that simple mixing of the concentrate with a detergent, or detergent and water will provide the finished consumer product.

Various changes and modifications in the acidic aqueous iodine concentrates herein disclosed may occur to those skilled in the art, and to the extent that such changes and modifications are embraced by the appended claims, it is to be understood that they constitute part of this invention. r

We claim:

1. An acidic aqueous iodine concentrate consisting essentially of an aqueous solution of hydroxyacetic acid, iodine and a water soluble iodide, with the amount of iodide (I-) being equal to at least one-half the amount by Weight of available iodine and sufficient to solubilize the iodine in said hydroxyacetic acid, said concentrate containing about 5 to 65% by Weight of hydroxyacetic acid and 5 to 45% by Weight of available iodine.

2. An acidic aqueous iodine concentrate as defined in claim 1, containing about 2 0 to 50% by Weight of hydroxyacetic acid and 10 to 25% by Weight of available iodine.

References Cited by the Examiner UNITED STATES PATENTS 2,977,278 3/ 1961 Shelanski et a1 167-70 FOREIGN PATENTS 825,676 12/1959 Great Britain.

OTHER REFERENCES Remingtons Practice of Pharmacy, 11th ed., Pa., Mack Publishing, 1956, pages 567-568.

5 SAM ROSEN, Primary Examiner.

FRANK CACCIAPAGLIA, JR., ENGENE FRANK,

VERA C. CLARKE, Examiners. 

1. AN ACIDIC AQUEOUS IODINE CONCENTRATE CONSISTING ESSENTIALLY OF AN AQUEOUS SOLUTION OF HYDROXYACETIC ACID, IODINE AND A WATER SOLUBLE IODIDE, WITH THE AMOUNT OF IODIDE (I-) BEING EQUAL TO AT LEAST ONE-HALF THE AMOUNT BY WEIGHT OF AVAILABLE IODINE AND SUFFICIENT TO SOLUBILIZE THE IODINE IN SAID HYDROXYACETIC ACID, SAID CONCENTRATE CONTAINING ABOUT 5 TO 65% BY WEIGHT OF HYDROXYACETIC ACID AND 5 TO 45% BY WEIGHT OF AVAILABLE IODINE. 